1. Field
The following description relates to an electrostatic (ESD) discharge device and method of fabricating the same. Such a device is configured to prevent ESD, a cause of product failure.
The following description also relates to a transient voltage suppressor (TVS) for an electrostatic discharge and method of fabricating the same which can improve TVS and ESDs feature by enlarging an area wherein a Zener diode is formed so as to be larger than alternatives.
2. Description of Related Art
A transient voltage suppressor or (TVS) is a general classification of an array of devices that are designed to react to sudden or momentary overvoltage conditions, to avoid negative consequences of such conditions. One such common device used for this purpose is known as the transient voltage suppression diode that is simply a Zener diode designed to protect electronics device against overvoltages. A Zener diode is a diode that allows current to flow in the forward direction in the same manner as an ideal diode, but a Zener diode also permits current to flow in the reverse direction when the voltage is above a certain value, known as the breakdown voltage.
Alternative semiconductor industry manufactured electrostatic discharge (ESD) protection devices use various methods and structures. In regards to international specifications, an example may be an ESD device standard that is able to respond to a high input voltage and current within one nanosecond. Such an example ESD device may correspond to a level 2 of IEC 61000-4-2 in International Electrotechnical Commission (IEC) guidelines and standards.
Some alternative ESD devices disclose structures wherein the ESD devices protect against effects of an ESD by employing a Zener diode and a P-N junction diode. A P-N junction diode occurs at a boundary between p-type and n-type doped semiconductors, and acts as a diode in that such a diode conducts in one direction. Generally, alternative ESD devices with acute breakdown voltage features have a problem of low capacitance. Such an acute breakdown voltage feature is required to provide low clamp voltages for an ESD device. In most cases, ESD devices generally have a greater capacitance than 1-6 pF. Such a type of device with large capacitance limits a response time of an ESD device.
Additionally, alternative ESD devices with relatively large capacitance value have slow response speeds and have a limitation in controlling their operation with a certain size clamp voltage in case a positive or a negative ESD event occurs.